Franks said there were all told, roughly 1,000 suspect sites to comb through where weapons of mass destruction might be stashed, with much of the work ahead.

"That work is not completed. And so I believe that we will either find the weapons or we will find evidence of the weapons of mass destruction. And I believe ... that will vindicate the intelligence that we received," Franks told a House Armed Services Committee hearing.

US military top brass were all convinced of the accuracy of the intelligence and the certainty of the threat posed by such weapons before and during the war, Franks said.

"The intelligence indicated to all of us that we should be prepared for weapons of mass destruction against our troops," he said.

"Intelligence is not perfect. It never will be," said Franks, who nevertheless said he was certain US-led forces would discover banned weapons in Iraq.

"I believe that the intelligence was worked hard. It was worked honestly. And our troops believed, as I believe, that we had better be prepared for the use of WMD on this battlefield."

When asked whether the White House had overstated the risk posed by ousted Iraqi president Saddam Hussein, Franks answered: "I do not believe that at all."

Military officials donned protective gear on numerous occasions during the war, and ordered troops to do the same, after US intelligence strongly indicated that a chemical attack was imminent, Franks said.

Franks' vote of confidence in US security did little to staunch the calls by Democrats for a full-scale investigation into US intelligence lapses leading up to the war.

One leading Democrat, Massachusetts Senator John Kerry, on Thursday lent his voice to the growing chorus of lawmakers calling for a thorough congressional probe.

"This is a national security issue for our country," he said at a press conference.

"The quality of our intelligence is critical, not just to the judgments that Congress makes but to our credibility in the world and to the capacity of the president to reach out to other countries and build the kind of coalitions we need to win the war on terror."

"I believe we need an open, thorough, complete and absolutely believable investigation into the quality of American intelligence so that going forward from now the national security interests of our country will be properly protected," said the Masschusetts senator, who is one of nine Democrats vying to represent his party in next year's presidential election.

Democrats' calls for more muscular congressional investigations into US intelligence followed White House revelations earlier this week that it relied on bogus information in making earlier claims that Iraq had tried to obtain nuclear materials from Africa.

In Pretoria, South Africa this week, US President George W. Bush maintained that even if isolated pieces of intelligence were flawed, the overall mission to overthrow Saddam was correct and just.

"There is no doubt in my mind that Saddam Hussein was a threat to the world peace and there is no doubt in my mind the United States along with our allies and friends did the right thing in removing him from power," Bush said.

Meanwhile, Secretary of State Colin Powell at a press conference Thursday called the charges of hyped intelligence "overwrought and overblown and overdrawn."

"Intelligence reports flow in from all over ... Sometimes it holds up, sometimes it does not hold up," he said.

"It's a moving train, and you keep trying to establish what is right and what is wrong," said Powell.

WAR.WIRE